At Work: Physicist Joseph Deasy

Dr. Deasy, Chair of the Department of Medical Physics and an expert in radiation therapy, talks about using physics to contribute to the fight against cancer.

Physicist Joseph O. Deasy joined Memorial Sloan Kettering Cancer Center in 2010 as Chair of the Department of Medical Physics and incumbent of the Enid A. Haupt Chair in Medical Physics. An expert in radiation therapy, Dr. Deasy is dedicated to developing new ways to optimize and plan treatments on a person-by-person basis.

While studying physics as a graduate student at the University of Kentucky, I became interested in applying my training to the medical field, in particular in oncology. I thought it would be fantastic to use physics to contribute to the fight against cancer.

I found that there are many opportunities for physicists and engineers to take part in this mission. At the University of Wisconsin, where I trained as a National Cancer Institute research fellow, I was fortunate to work with a group of highly talented physicists who were developing intensity-modulated radiation therapy (IMRT), an advance in treatment methods in which a tumor is targeted with multiple radiation beams at different angles and intensities. With this added flexibility, high radiation doses can be shaped to conform to each particular patient’s tumor volume, while giving much lower doses to sensitive normal tissues surrounding the tumor, which considerably reduces the toxic side effects of the therapy.

I thought it would be fantastic to use physics to contribute to the fight against cancer.

Joseph O. DeasyChair, Department of Medical Physics

As a researcher at the Washington University School of Medicine, I spent more than a decade developing mathematical models and other methods for optimizing and planning radiation treatment protocols. My colleagues and I created freely available computer software that now is being used by hundreds of physicists and physicians around the world to analyze radiation dose distributions and share research results.

We use the software to develop models that can predict whether a treatment is likely to result in a complication. For example, such models can assess whether treatment for lung cancer is likely to cause a potentially life-threatening lung inflammation, or whether a head and neck cancer treatment is likely to cause a permanent dry mouth by damaging the salivary glands.

Over the years, we have studied how to take biological factors as well as physical parameters into account. Such biological factors include blood levels of certain proteins that have been shown to make some people more likely to have a radiation-induced complication. In the future, we hope to combine both biological factors and control over the dose distribution to improve treatments for individual patients.

I have been at Memorial Sloan Kettering for the past two years, and it’s an extraordinary honor to be part of one of the world’s leading institutions in medical physics. Our physicians, physicists, and engineers have pioneered the development and clinical implementation of numerous technologies that now are widely used for cancer treatment and diagnosis — methods like IMRT and quantitative PET imaging, to mention just two.

Medical physicists use CT images, such as this one of a patient with prostate cancer, to plan individual radiation treatments. A dose-distribution calculation, indicated with various colors surrounding the target (in pink), shows where the radiation will be concentrated as well as sensitive tissues to avoid.

Today, our medical physics department employs more than 170 staff members. Many of our experts work alongside clinicians to plan and monitor treatments and imaging procedures. We are also responsible for assessing the performance and proper use of more than 10,000 medical instruments used in the hospital, as well as ensuring that radiation is always used safely.

In addition, medical physics investigators collaborate with radiation oncologists, radiologists, surgeons, and medical oncologists on a wide range of projects. One growing area of research is the development of new applications of advanced imaging technologies, such as MRI and PET, which I believe will be increasingly important for personalized medicine.

For example, we are investigating ways to combine information from multiple kinds of MRI scans using computational modeling, statistics, and machine learning, which is a type of artificial intelligence. By imaging a tumor before, during, and after the treatment, we might be able to deliver radiation more precisely while tracking how the tumor responds to the treatment over time. Working with radiation oncologists, we are testing the idea that treatment could take into account the predicted shrinkage of a lung tumor, right from the beginning of therapy, allowing us to deliver a higher radiation dose without increased toxicity.

Working with radiologists and epidemiologists, we are learning how to extract clinically meaningful information from MRIs to make cancer screening programs more effective. In women undergoing screening for breast cancer, such imaging data could potentially be used to identify those who are at high risk for developing the disease later in life, so that women at lower risk might be spared from having invasive tests they don’t need. Potentially, blood tests might be added to screening to make the process even more effective.

The intersection between physics, biology, and medicine is truly fascinating. I enjoy collaborating with physicians, who know what the real clinical problems are. As a physicist, it’s fun and rewarding to work on difficult problems that can lead to improvements in the lives of our patients.

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Comments

Robert Schenter, PhD

Feb 28, 2013 • 3:28 PM

Dr. Deasy, I ave been involved with the production of medical isotopes in fission reactor and charged particle accelerator systems for the past 33
years. I continue to this work mainly trying to get commercial companies "off
the ground" in their abilities to supply medical isotopes which are in short supply in the US.
My question is how does you group relate to Dr. Scheinberg's group
which uses medical isotopes extensively.
Thanks.

Thank you for your comment! We spoke with Dr. Deasy and he says: "Several physicists from our department work with researchers in Dr. Scheinberg's group to support the use of medical isotopes. Let us know if you have a more specific question we can answer."

Robert Schenter, PhD

Feb 28, 2013 • 7:19 PM

Is there any expectation by Dr. Scheinberg's group to get into "Killing HIV Virus"
with alpha emitters in the future. I think David might have mentioned this way back when in the Fernald talk days. I submitted 2 proposals on this to the Gates Foundation 2008 and 2009. The Einstein group(Dadachova) recently got $100,000 from Gates in 2011 on this. They get their Ac225 from German cyclotrons.
Thanks.
BobS

Robert, we spoke to Dr. Scheinberg and he said, "Yes, we tried this about 19 years ago and were not too successful. I think we were not able to get a high enough specific activity to kill with the low number of target sites. If you want to follow up on ideas or collaborations, contact Mike McDevitt here." You can find Dr. McDevitt's information here: http://www.mskcc.org/cancer-care/doctor/michael-mcdevitt Thanks for your comment!

Robert Schenter, PhD

Mar 1, 2013 • 11:08 AM

Great. Thanks. I will contact Dr. McDevitt. May I have his email address?

Pat Vee

Mar 1, 2013 • 5:19 PM

I have lost the use of my right hand due to radiation damage as part of treatment for breast cancer over 5 years ago. Radiation destroyed the median & ulner nerves in the brachial plexus. I take large doses of narcotics & Neurontin for the excruciating nerve pain in my right hand, yet they provide little relief.

Dear Dr. Deasy, as an expert in radiation:

Is there any current treatment available to relieve or reduce the pain from radiation damage to nerves? Is there anything to heal or numb the nerves so as to reduce or eliminate the nerve pain? Is there anyone I may consult to improve my quality of life?

We're sorry but we are not able to answer personal medical questions on our blog. If you'd like to make an appointment with a Memorial Sloan-Kettering physician, please call 800-525-2225 or go to http://www.mskcc.org/cancer-care/appointment. Thanks for your comment.

Pat Vee

Mar 1, 2013 • 8:53 PM

I was looking for information on new programs that may be available after radiation damage. I think it's something Dr. Deasy, as an expert in radiation, might know. I am not asking a personal medical question per se. Radiation does do damage. I'd like to know if there is treatment available to relieve or reduce the pain from radiation damage to nerves? And, if there is anything to heal or numb the nerves so as to reduce or eliminate nerve pain? I would appreciate an answer from Dr. Deasy. I have not been able to find the answers through my own research.

I am aware of what's available at MSKCC however, that's not what I'm looking for. Dr. Deasy is an expert in radiation and radiation does at times cause residual nerve damage. I would like to know from Dr. Deasy himself if he has any information on new programs, outside of MSKCC, that may be available for treatment and/or innovative care of residual radiation nerve damage?

Walter Kucaba

Apr 27, 2013 • 10:42 AM

I was curious as to any efforts in using nanotechnology for the detection of early stage breast CA with the new SQIUD technology using Magnetic relaxometry by Dr. Edward Flynn at the Los Alamos Lab? Thanks for help.

Walter, we shared your question with Dr. Deasy, who said that it looks like interesting technology. However, it is in early phases of clinical testing and we are not actively using it ourselves. Thank you for your comment.

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We welcome your questions and comments. While we share many of them with our world-class doctors and researchers, we regret that in order to protect your privacy, we are not able to make personal medical recommendations on this forum, nor do we publish comments that contain your personal information. If you would like to consult with an MSK doctor, we encourage you to make an appointment at 800-525-2225 or request an appointment online.